#include "header.h"


void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT); // xoa moi pixel
	glColor3f(1.0 , 1.0 , 1.0); // thiet lap mau ve - mau trang
	glBegin(GL_POLYGON); // bat dau ve
		glVertex3f(0.25, 0.25 , 0);
		glVertex3f(0.25, 0.75 , 0);
		glVertex3f(0.75, 0.75 , 0);
		glVertex3f(0.75, 0.25 , 0);
	glEnd(); // ket thuc ve da giac
	glFlush();
}

// thiet lap cac ham khoi tao
void init(void)
{
	glClearColor(0.0 , 0.0 , 0.0 , 0.0) ; //phu nen mau den;
	// thiet lap thong so view
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, 1.0 , 0.0 , 1.0, -1.0 , 1.0);
}